The primary aim of this proposal is to investigate the normative development of the neurobiology that results in mental illness associated with emotional difficulties including high reactivity and poor regulation. Such illnesses include, but are not limited to, anxiety, depression, schizophrenia, bipolar disorder, sociopathy, and personality disorders. A failure to effectively recruit a neural circuitry that includes the amygdala and ventromedial prefrontal cortex has been implicated in these mental illnesses in adults. The present research strategy, which uses structural and functional magnetic resonance imaging (MRI) and behavioral measures, will employ a prospective and longitudinal design that identifies biomarkers associated with these difficulties and map their development as children age into adolescence. The second aim is to examine the influence of early adverse caregiving environments on the development of this neurobiology. For long, it has been recognized that environmental stress is associated with a disproportionately high of risk emotional psychopathology. A large animal literature combined with an emerging human neuroimaging literature shows that environmental stress can impair mental health functioning via disruption of the amygdala and the regulatory processes that depend on proper connectivity between amygdala and ventromedial prefrontal cortex. When stress exposure occurs prior to developmental maturity, the effects can be more potent and its impact longer lasting than stress that occurs in adulthood. Therefore, the findings of this project will have a high impact on the field of mental health by identifying biomarkers associated with emotional difficulties prior to their behavioral onset. In this way, we will be better at predicting and preventing the development of mental illnesses that often emerge during the adolescent period.